Data interpolation from graph

Dear Experts,

I have x1 (first column of Book1 excel sheet) and y1 (2nd column of excel sheet Book1). From this data I want to interpolate the y2 data for the x2 (1st column of excel sheet Book2). How to do it ?

Answer 1

[Andrea Monfredini]

n = 10; %the sample size
x1 = linspace(0,5,n); %this is to simulate your x1
y1 = rand(1,n); %this is to simulate your y1 

p = polyfit(x1,y1,n)

x2 = linspace(0,5,10000); %this is to simulate x2, that should be the domain of the interpolating function
y2 = polyval(p,x2)

scatter(x1,y1)
hold on;
plot(x2,y2)